As mentioned, Tilapia is another fish to consider. However, I don't think they will make it thru a Texas winter and the reason they don't ( I think ) is because you are only allowed to stock a certain species of them that aren't as cold tolerant. Now you could keep some breeders over winter, and raise your own, but its a fair amount of work. I have been trying just this, and wouldn't recommend it for just anyone. I wonder how Tilapia compares to Carp to CJB ideas of the most bang per acre? The tilapia would go nicely with Spark's idea of a mass harvest once a year, in the fall. Something I am considering myself this fall if things work out. With the tilapia tho, you might need to feed them if you go with them densely stocked, which sounds like you rather not do.
I have a bit of a self-sustaining mind set too. Not because of the things Spark eludes to (He's afraid Yolk is after him, can't say I blame him
). My pond is stocked much the same way as CJB is recommending. The one difference is I stocked smaller numbers, but began with larger fish. So far all is going good. You still can adjust it and try things like tilapia, trout, and a few other types with out getting to bad. I have messed with these for fun, but has let me get ample table fare till the other species really get going.
With 1/2 acre, you could also consider pumping it down/out to make a harvest easier.
